feat: add Command ClassBuilder

.changeset/cool-vans-tan.md

@@ -0,0 +1,5 @@
+---
+"@smithy/smithy-client": minor
+---
+
+add Command classBuilder

packages/smithy-client/src/command.spec.ts

@@ -0,0 +1,38 @@
+import { Command } from "./command";
+
+describe(Command.name, () => {
+  it("implements a classBuilder", async () => {
+    class MyCommand extends Command.classBuilder<any, any, any, any, any>()
+      .ep({
+        Endpoint: { type: "builtInParams", name: "Endpoint" },
+      })
+      .m(function () {
+        return [];
+      })
+      .s("SmithyMyClient", "SmithyMyOperation", {})
+      .n("MyClient", "MyCommand")
+      .f()
+      .ser(async (_) => _)
+      .de(async (_) => _)
+      .build() {}
+
+    const myCommand = new MyCommand({
+      Prop: "prop1",
+    });
+
+    expect(myCommand).toBeInstanceOf(Command);
+    expect(myCommand).toBeInstanceOf(MyCommand);
+    expect(MyCommand.getEndpointParameterInstructions()).toEqual({
+      Endpoint: { type: "builtInParams", name: "Endpoint" },
+    });
+    expect(myCommand.input).toEqual({
+      Prop: "prop1",
+    });
+
+    // private method exists for compatibility
+    expect((myCommand as any).serialize).toBeDefined();
+
+    // private method exists for compatibility
+    expect((myCommand as any).deserialize).toBeDefined();
+  });
+});

packages/smithy-client/src/command.ts

@@ -1,5 +1,21 @@
+import { EndpointParameterInstructions } from "@smithy/middleware-endpoint";
 import { constructStack } from "@smithy/middleware-stack";
-import { Command as ICommand, Handler, MetadataBearer, MiddlewareStack as IMiddlewareStack } from "@smithy/types";
+import type { HttpRequest } from "@smithy/protocol-http";
+import type {
+  Command as ICommand,
+  FinalizeHandlerArguments,
+  Handler,
+  HandlerExecutionContext,
+  HttpRequest as IHttpRequest,
+  HttpResponse as IHttpResponse,
+  Logger,
+  MetadataBearer,
+  MiddlewareStack as IMiddlewareStack,
+  Pluggable,
+  RequestHandler,
+  SerdeContext,
+} from "@smithy/types";
+import { SMITHY_CONTEXT_KEY } from "@smithy/types";
 
 /**
  * @public
@@ -11,11 +27,256 @@ export abstract class Command<
   ClientInput extends object = any,
   ClientOutput extends MetadataBearer = any
 > implements ICommand<ClientInput, Input, ClientOutput, Output, ResolvedClientConfiguration> {
-  abstract input: Input;
-  readonly middlewareStack: IMiddlewareStack<Input, Output> = constructStack<Input, Output>();
+  public abstract input: Input;
+  public readonly middlewareStack: IMiddlewareStack<Input, Output> = constructStack<Input, Output>();
+
+  /**
+   * Factory for Command ClassBuilder.
+   * @internal
+   */
+  public static classBuilder<
+    I extends SI,
+    O extends SO,
+    C extends { logger: Logger; requestHandler: RequestHandler<any, any, any> },
+    SI extends object = any,
+    SO extends MetadataBearer = any
+  >() {
+    return new ClassBuilder<I, O, C, SI, SO>();
+  }
+
   abstract resolveMiddleware(
     stack: IMiddlewareStack<ClientInput, ClientOutput>,
     configuration: ResolvedClientConfiguration,
     options: any
   ): Handler<Input, Output>;
+
+  /**
+   * @internal
+   */
+  public resolveMiddlewareWithContext(
+    clientStack: IMiddlewareStack<any, any>,
+    configuration: { logger: Logger; requestHandler: RequestHandler<any, any, any> },
+    options: any,
+    {
+      middlewareFn,
+      clientName,
+      commandName,
+      inputFilterSensitiveLog,
+      outputFilterSensitiveLog,
+      smithyContext,
+      additionalContext,
+      CommandCtor,
+    }: ResolveMiddlewareContextArgs
+  ) {
+    for (const mw of middlewareFn.bind(this)(CommandCtor, configuration)) {
+      this.middlewareStack.use(mw);
+    }
+    const stack = clientStack.concat(this.middlewareStack);
+    const { logger } = configuration;
+    const handlerExecutionContext: HandlerExecutionContext = {
+      logger,
+      clientName,
+      commandName,
+      inputFilterSensitiveLog,
+      outputFilterSensitiveLog,
+      [SMITHY_CONTEXT_KEY]: {
+        ...smithyContext,
+      },
+      ...additionalContext,
+    };
+    const { requestHandler } = configuration;
+    return stack.resolve(
+      (request: FinalizeHandlerArguments<any>) => requestHandler.handle(request.request as HttpRequest, options || {}),
+      handlerExecutionContext
+    );
+  }
+}
+
+/**
+ * @internal
+ */
+type ResolveMiddlewareContextArgs = {
+  middlewareFn: (CommandCtor: any, config: any) => Pluggable<any, any>[];
+  clientName: string;
+  commandName: string;
+  smithyContext: Record<string, unknown>;
+  additionalContext: HandlerExecutionContext;
+  inputFilterSensitiveLog: (_: any) => any;
+  outputFilterSensitiveLog: (_: any) => any;
+  CommandCtor: any /* Command constructor */;
+};
+
+/**
+ * @internal
+ */
+class ClassBuilder<
+  I extends SI,
+  O extends SO,
+  C extends { logger: Logger; requestHandler: RequestHandler<any, any, any> },
+  SI extends object = any,
+  SO extends MetadataBearer = any
+> {
+  private _init: (_: Command<I, O, C, SI, SO>) => void = () => {};
+  private _ep: EndpointParameterInstructions = {};
+  private _middlewareFn: (CommandCtor: any, config: any) => Pluggable<any, any>[] = () => [];
+  private _commandName = "";
+  private _clientName = "";
+  private _additionalContext = {} as HandlerExecutionContext;
+  private _smithyContext = {} as Record<string, unknown>;
+  private _inputFilterSensitiveLog = (_: any) => _;
+  private _outputFilterSensitiveLog = (_: any) => _;
+  private _serializer: (input: I, context: SerdeContext | any) => Promise<IHttpRequest> = null as any;
+  private _deserializer: (output: IHttpResponse, context: SerdeContext | any) => Promise<O> = null as any;
+  /**
+   * Optional init callback.
+   */
+  public init(cb: (_: Command<I, O, C, SI, SO>) => void) {
+    this._init = cb;
+  }
+  /**
+   * Set the endpoint parameter instructions.
+   */
+  public ep(endpointParameterInstructions: EndpointParameterInstructions): ClassBuilder<I, O, C, SI, SO> {
+    this._ep = endpointParameterInstructions;
+    return this;
+  }
+  /**
+   * Add any number of middleware.
+   */
+  public m(
+    middlewareSupplier: (CommandCtor: any, config: any) => Pluggable<any, any>[]
+  ): ClassBuilder<I, O, C, SI, SO> {
+    this._middlewareFn = middlewareSupplier;
+    return this;
+  }
+  /**
+   * Set the initial handler execution context Smithy field.
+   */
+  public s(
+    service: string,
+    operation: string,
+    smithyContext: Record<string, unknown> = {}
+  ): ClassBuilder<I, O, C, SI, SO> {
+    this._smithyContext = {
+      service,
+      operation,
+      ...smithyContext,
+    };
+    return this;
+  }
+  /**
+   * Set the initial handler execution context.
+   */
+  public c(additionalContext: HandlerExecutionContext = {}): ClassBuilder<I, O, C, SI, SO> {
+    this._additionalContext = additionalContext;
+    return this;
+  }
+  /**
+   * Set constant string identifiers for the operation.
+   */
+  public n(clientName: string, commandName: string): ClassBuilder<I, O, C, SI, SO> {
+    this._clientName = clientName;
+    this._commandName = commandName;
+    return this;
+  }
+  /**
+   * Set the input and output sensistive log filters.
+   */
+  public f(
+    inputFilter: (_: any) => any = (_) => _,
+    outputFilter: (_: any) => any = (_) => _
+  ): ClassBuilder<I, O, C, SI, SO> {
+    this._inputFilterSensitiveLog = inputFilter;
+    this._outputFilterSensitiveLog = outputFilter;
+    return this;
+  }
+  /**
+   * Sets the serializer.
+   */
+  public ser(
+    serializer: (input: I, context?: SerdeContext | any) => Promise<IHttpRequest>
+  ): ClassBuilder<I, O, C, SI, SO> {
+    this._serializer = serializer;
+    return this;
+  }
+  /**
+   * Sets the deserializer.
+   */
+  public de(
+    deserializer: (output: IHttpResponse, context?: SerdeContext | any) => Promise<O>
+  ): ClassBuilder<I, O, C, SI, SO> {
+    this._deserializer = deserializer;
+    return this;
+  }
+  /**
+   * @returns a Command class with the classBuilder properties.
+   */
+  public build(): {
+    new (input: I): CommandImpl<I, O, C, SI, SO>;
+    getEndpointParameterInstructions(): EndpointParameterInstructions;
+  } {
+    // eslint-disable-next-line @typescript-eslint/no-this-alias
+    const closure = this;
+    let CommandRef: any;
+
+    return (CommandRef = class extends Command<I, O, C, SI, SO> {
+      /**
+       * @public
+       */
+      public static getEndpointParameterInstructions(): EndpointParameterInstructions {
+        return closure._ep;
+      }
+
+      /**
+       * @public
+       */
+      public constructor(readonly input: I) {
+        super();
+        closure._init(this);
+      }
+
+      /**
+       * @internal
+       */
+      public resolveMiddleware(stack: IMiddlewareStack<any, any>, configuration: C, options: any): Handler<any, any> {
+        return this.resolveMiddlewareWithContext(stack, configuration, options, {
+          CommandCtor: CommandRef,
+          middlewareFn: closure._middlewareFn,
+          clientName: closure._clientName,
+          commandName: closure._commandName,
+          inputFilterSensitiveLog: closure._inputFilterSensitiveLog,
+          outputFilterSensitiveLog: closure._outputFilterSensitiveLog,
+          smithyContext: closure._smithyContext,
+          additionalContext: closure._additionalContext,
+        });
+      }
+
+      /**
+       * @internal
+       */
+      // @ts-ignore used in middlewareFn closure.
+      public serialize = closure._serializer;
+
+      /**
+       * @internal
+       */
+      // @ts-ignore used in middlewareFn closure.
+      public deserialize = closure._deserializer;
+    });
+  }
+}
+
+/**
+ * A concrete implementation of ICommand with no abstract members.
+ * @public
+ */
+export interface CommandImpl<
+  I extends SI,
+  O extends SO,
+  C extends { logger: Logger; requestHandler: RequestHandler<any, any, any> },
+  SI extends object = any,
+  SO extends MetadataBearer = any
+> extends Command<I, O, C, SI, SO> {
+  readonly input: I;
+  resolveMiddleware(stack: IMiddlewareStack<SI, SO>, configuration: C, options: any): Handler<I, O>;
 }